Biologic constructs, which include “regenerative tissue matrices” “acellular tissue matrices” or “collagen scaffolds” and other such substances, are small sheets or disks of flexible, engineered biomaterial, such as collagen or fibrin, decellularized dermal matrix crosslinked and sterilized xenograft tissues, and “platelet-rich-plasma” patches sometimes totally devoid of living cell material and sometimes loaded with active adjuncts such as biologic growth factors. Biologic constructs may also be tissue-engineered from mesenchymal stem cells. For the purposes of this application, the term biologic construct refers to any sheet-like or disc-like configuration of regenerative tissue matrix, acellular tissue matrices or collagen scaffolds, or similar materials suitable for placement within the body to promote healing.
Biologic constructs and implants are growing rapidly in popularity for the repair of joint pathologies. Biologic constructs may be a new alternative for carpal arthroplasty in patients with clinical conditions such as osteonecrosis. Biologic constructs are a family of biologically derived implants to promote tissue growth or to patch and repair tissue defects and tears. These include the repair of arthritic cartilage, the joining of tendons to bone and the bridging of degenerated rotator cuff in the shoulder. Biologic constructs, and graft material such as platelet rich fibrin membrane, acellular dermal allograft, (MTF) and xenograft materials (Pegasus Biologics) and graft patches (Wright Medical Graftjacket) have enabled the reconstruction and treatment of previously untreatable and irreparable musculoskeletal injuries and pathologies. Biologic constructs now occupy an increasingly important place in the orthopedic surgeons armamentarium.
One of the key problems with biologic constructs is that the delivery instrumentation has not kept pace with advances in these implants. For example, fluid seals effectively hold fluid, but do not allow passage of sutures and metal instruments through the biologic constructs without tearing and damage. This can render the construct useless, and add significantly to the cost of the case, as these implants can be fragile as well as expensive. A damaged implant can result in several hundred dollars of added expense.
In addition to these constructs being soft, floppy, and prone to damage from tearing, suture management is very difficult, both during the preparation of the implant outside the patient as well as managing the implant and sutures when the implant is manipulated and attached in the joint. Currently an implant construct is hand-held with hemostats by an assistant while the graft is prepared with sutures.
An important clinical need exists to make these biologic constructs easier to prepare, handle, deliver, and implant so that the potential of these important advances in biologics can be fully realized.